I prefer to use DNS, but I’ll explain more below. I think the key take away is that if you’re deploying SBS servers in client-environments, then you should really have a process in-place to ensure quality and uniformity across the environments that you support. Certainly, there are a few specific circumstances where you probably need deviate from the “standard”, but these should be the exception and not the rule.

So why use DNS? I actually think the case for why you should not use the ISP/SmartHosts is a better argument. For instance, if you’re forwarding though the ISP email originating from your organization will show that it was forwarded though the ISP in the header. Secondly, since UCE/spam also uses this method, it increases the likelihood of the mail not being delivered, and some domains refuse to accept mail that has been passed though a mail forwarder. There are more reasons too… maybe your ISP gets added to a RBL – and suddenly you’re blocked by extension.

1 comment:

Anonymous
said...

I agree DNS is a much better way to route email. I'd like to know what steps you take to ensure that SPAM programs don't filter out your DNS routed email. When running CEICW it's typically domainname.com ...but when you create an MX record with your ISP it's mail.domainname.com which doesn't match the SMTP header info created by CEICW. I've asked many ISP's to create PTR records to aid spam filters with reverse DNS lookuup etc. Some accomodate others just say the record is not needed and won't do it.